dd-trace

Tracing

This feature allows you to trace the execution of your application, marking and timing various operations within your code. You can tag spans with metadata and monitor the performance of individual requests or tasks.

const tracer = require('dd-trace').init();

// Instrument a function
tracer.trace('web.request', (span) => {
  // Do some work
  span.setTag('http.status_code', 200);
});

Automatic Instrumentation

dd-trace can automatically instrument popular libraries and frameworks such as Express, Koa, GraphQL, and many others. This means that you can get insights into how these libraries are performing without having to manually instrument code.

const tracer = require('dd-trace').init();

// Automatically instruments supported libraries
const express = require('express');
const app = express();

app.get('/', (req, res) => res.send('Hello World!'));
app.listen(3000);

Custom Tags and Metrics

You can add custom tags and metrics to your traces to provide additional context and granularity. This can be useful for filtering and searching through your traces in the Datadog APM interface.

const tracer = require('dd-trace').init();

// Add custom tags to a span
tracer.trace('web.request', (span) => {
  span.setTag('my_tag', 'my_value');
  span.setMetric('my_metric', 100);
});

Distributed Tracing

Distributed tracing allows you to trace requests as they move across different services and components in your system. This is essential for understanding the performance of microservices architectures.

const tracer = require('dd-trace').init();

// Continue a trace across asynchronous boundaries
async function part1() {
  return tracer.trace('part1', async () => {
    // Do something
  });
}

async function part2() {
  return tracer.trace('part2', async (span) => {
    // Do something else
    span.context().toTraceId();
  });
}